Ultrasonic Sanitation Device and Associated Methods

ABSTRACT

A device for sanitizing a space includes a tank having an interior space for holding an aqueous sanitizing liquid. A reactor vessel is supported within the interior space and above a bottom of the tank. A liquid depth in the tank interior space is maintained at a level beneath a top edge of the reactor vessel. An ultrasonic head comprising an ultrasonically vibratable disc for generating ultrasonic energy is positionable within and beneath the top edge of the reactor vessel. Liquid is transferrable from the tank interior space to the reactor vessel to a level for substantially submerging the ultrasonic head. The disc is vibrated to form an atomized fog of particles from the aqueous sanitizing liquid. The formed atomized fog is exhausted from the reactor vessel to a space exterior of the tank. A sanitizing composition is also provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to systems and methods for sanitizingenclosed spaces, and, more particularly, to such systems and methodsthat are capable of treating spaces three-dimensionally.

2. Description of Related Art

The sanitization and disinfection of enclosed spaces has become an issueof increasing importance owing to the possible presence of both naturaland deliberately introduced contaminants. Since most commercialbuildings are “sealed,” that is, their windows cannot be opened,circulation of “fresh” air is typically not possible within a particularroom. Similarly, most houses are now effectively sealed, with mostlyprocessed air being circulated. In addition, some forms of conveyance,especially airplanes, are of necessity sealed against the environmentduring flight.

The enclosed nature of modern spaces has led to such problems as “sickbuilding syndrome,” since molds and mildews can flourish in enclosed,damp environments, and also to the possibility of the deliberateintroduction of more insidious threats to life, such as biological andchemical agents.

At present most sanitizing and disinfecting agents are“two-dimensional,” that is, they are applied to accessible surfaces. Forexample, when cleaning a table, typically the cleanser is applied to thetable top, but not the underside.

“Fogging” agents are known for eradicating pests such as fleas and otherinsects. Ionization-type purifiers are also known in the art that useelectrostatic means to collect allergens and pollutants.

Therefore, it would be beneficial to provide a more effective device,system, and method for sanitizing enclosed spaces in a three-dimensionalfashion.

SUMMARY OF THE INVENTION

The present invention provides a device for sanitizing a space. Thedevice comprises a tank having an interior space for holding an aqueoussanitizing liquid. A reactor vessel is supported within the interiorspace and above a bottom of the tank. Means are provided for maintaininga liquid depth in the tank interior space to a level beneath a top edgeof the reactor vessel. An ultrasonic head comprising an ultrasonicallyvibratable disc for generating ultrasonic energy is positionable withinand beneath the top edge of the reactor vessel. Means are included fortransferring liquid from the tank interior space to the reactor vesselto a level for substantially submerging the ultrasonic head. Means arealso provided for vibrating the disc to form an atomized fog ofparticles from the aqueous sanitizing liquid. Further means are providedfor exhausting the formed atomized fog from the reactor vessel to aspace exterior of the tank.

The device may also be used to distribute a liquid by creating theatomized fog as above and directing the fog to a desired location, forexample, for delivering fertilizer or pesticide to a plot of land, forwatering plants, or for distributing a skin-care product to the skin ofa user, although these uses are not intended to be limiting.

The device of the present invention is able to reach all areas in aspace where air can penetrate, and, since the atomized particles havebeen found to remain airborne longer than conventional mists, treatmentis more thorough, and less chemical is required than used by previouslyknown devices. A typical room of dimensions 12×12×10 ft can bedisinfected in 10 min or less, for example.

The features that characterize the invention, both as to organizationand method of operation, together with further objects and advantagesthereof, will be better understood from the following description usedin conjunction with the accompanying drawing. It is to be expresslyunderstood that the drawing is for the purpose of illustration anddescription and is not intended as a definition of the limits of theinvention. These and other objects attained, and advantages offered, bythe present invention will become more fully apparent as the descriptionthat now follows is read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross-sectional view of an embodiment of the sanitizingdevice of the present invention.

FIG. 2 is a rear view of the device of FIG. 1.

FIG. 3 is an exploded perspective view of the reactor tray of the deviceof FIG. 1.

FIG. 4 is a side view of the reactor tray.

FIG. 5 is a rear view of the reactor tray.

FIG. 6 is a top view of the reactor tray with ultrasonic headspositioned therein.

FIG. 7 is a side-top perspective view of an ultrasonic reactor head,with one disk seen in exploded view.

FIG. 8 is an exploded view of a reactor head disk.

FIG. 9 is a side perspective view of an alternate embodiment of anexhaust system including a diverter element.

FIG. 10 is a side cross-sectional view of an alternate embodimentincorporating a heating exhaust.

FIGS. 11A-11D are side cross-sectional views of different exemplaryembodiments of the reactor tray.

FIG. 12 is a schematic illustration of a side view of a device having adifferently shaped tank.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description of the preferred embodiments of the present invention willnow be presented with reference to FIGS. 1-12. The device 10 forsanitizing a space includes a tank 11 (FIGS. 1 and 2) that has aninterior space 12 for holding an aqueous sanitizing liquid 13. In aparticular embodiment, the tank's top end 14 is substantially smallerthan its bottom 15. Further, the tank 11 may be configured for placementupon a wheeled cart 16 for ease of transport.

The tank 11 has a liquid line aperture 17 adjacent the top 14 and aliquid outlet 18 adjacent the bottom 15. The tank 11 can comprise amaterial adapted to maintain a static charge, such as, but not intendedto be limiting, a high-density polyethylene (HDPE) material.

A fog outlet 19 is positioned adjacent the tank's top 14 along the rearwall 20, and is in fluid communication with a chimney 21 having a bore22 therethrough leading to a space 23 exterior of the tank 11. In apreferred embodiment, the chimney bore 22 has an elbow therein, shown bythe dotted line in FIG. 1, meeting the fog outlet 19 at a first end 24and the exterior space 23 at the second, upwardly directed end 25.

A reactor vessel 26 is supported within the tank's interior space 12 andabove the tank's bottom 15. In a particular embodiment illustrated inFIGS. 3-5, not intended to be limiting, the reactor vessel 26 comprisesa substantially hollow rectangular lower section 27 that has a pluralityof support legs 28 that extend from a bottom 29 thereof. An uppersubstantially rectangular section 30 comprises a bottom 31 and fourenclosing walls 32 that extending upwardly from the upper section'sbottom 31 and are adapted to contain liquid in the interior space 33formed thereby. The lower 27 and the upper 30 sections are affixabletogether with the upper section 30 atop the lower section 27 and arepositionable within the tank's interior space 12 with the support legs28 contacting the bottom surface 34 of the tank's interior space 12. Oneof skill in the art will recognize that additional embodiments for thereactor tray 26 could be envisioned, and that the shape presented herein is intended to be exemplary only.

In a particular embodiment, not intended to be limiting, the reactorvessel 26 is formed in two parts 27,30 in order to permit insertion intoa particular tank 11. Here the parts 27,30 are held together with theuse of joiner clips 35 that are screwed onto the lower section 27 andserve to brace the sections 27,30 together. The reactor vessel 26 hasone or more drain holes 36 extending from the interior space 33 of thereactor vessel 26 through to the tank's interior space 12 and ispositioned adjacent the bottom 31 of the reactor vessel's interior space33.

The reactor vessel 26 further has affixed thereto a hose clamp 38 forsupporting a liquid line 39, which will be discussed in the following.The top surface 40 of the upper section 30 should preferably have anarea substantially greater than the top 14 of the tank 11.

Another feature of the reactor vessel 26 is that the top edge 41 of theupper section 30 has a plurality of notches 42 therealong. These notches42 have been found important in permitting liquid to pass therethrough,but to substantially prevent foam from passing therethrough, thusretaining foam within the upper section 30 and not permitting it intothe return line 39.

Positioned within the reactor vessel's upper section 30 is a pluralityof ultrasonic heads 43, here, three ultrasonic heads (FIGS. 6-8). Eachof the heads 43 comprises a plurality, here, nine, vibratable discs 44for generating ultrasonic energy. The heads 43 are positioned so as tobe submersible within the reactor vessel 26, the submersion depth 45optimized for production of an atomized fog 46 of particles from theliquid 13 therewithin. Preferably the fog 46 comprises negativelycharged particles, which aid dispersal and space coverage. It has beenfound that the depth 45 of the liquid column and also the vibrationfrequency affects the focus of the sound waves. The signal foractivating the discs 44 is transmitted from devices known in the art,such as by way of a manual switch or level sensor.

The ultrasonic heads 43 believed at the time of filing to represent abest mode of carrying out the invention comprise heads obtained fromSonaer Ultrasonics (Farmingdale, N.Y.). An exemplary head that can beused comprises part number T241, although this is not intended to belimiting. The fog 46 created by these heads 43 can contain particles ina range of 0.25-5.0 μm, although this is not intended to be limiting, asthe size may be larger in some instances. Each of the discs 44 include asubstantially toroidal O-ring seat 47, a Viton O-ring 48 seated on theO-ring seat 47, a ceramic disk 49 positioned atop the O-ring 48, and asubstantially toroidal retaining ring 50 positioned in circumferentiallyretaining relation atop the ceramic disk 49. The discs 44 are known inthe art to be supplied with silicone O-rings, but it has been found thatthe increased stiffness and chemical resistance of the Viton material isbeneficial to the invention.

The drain hole 36 discussed above has been found to be beneficial inextending the life of the device 10 by keeping the heads 43 dry. A levelsensor 51 can also be provided for automatically turning the heads 43 onand off depending upon the presence or absence of liquid. The levelsensor 51 can be positioned either on the tank 11 or on the heads 43themselves.

Means are included for transferring liquid from the tank's interiorspace 12 to the reactor vessel 26 to a level for substantiallysubmerging the ultrasonic head 43. For this purpose is provided a liquidline 39 that is in fluid communication with the tank's liquid outlet 18at an inlet end 53 and with the reactor vessel 26 at an outlet end 54.The liquid line 39 in this embodiment passes through the liquid lineaperture 17 between the inlet end 53 and the outlet end 54, and isaffixed to the reactor vessel 26 with the use of the hose clamp 38.

A pump 55 is provided along the liquid line 39 that is operable to moveliquid 13 through the liquid line 39 from the tank's interior space 12beneath the reactor vessel 26 to the interior space 33 of the reactorvessel 26. Preferably the liquid line 39 comprises a substantially clearmaterial, so that a portion 56 of the liquid line 39 exterior of thetank 11 can thereby serve as an indicator of a liquid level within thetank's interior space 12 when the pump 55 is not operating. Theplacement of the liquid line portion 56 outside the tank 11 has alsoproven beneficial in assisting in cooling the liquid upon its pathway tothe reactor vessel 26. In addition, a filtration element may be added toeliminate contaminants along the liquid line 39.

The device 10 further includes means for exhausting the atomized fog 46that is formed to an exterior of the tank 11. This can be accomplished,for example, with the use of a fan 57 positioned within the tank'sinterior space 12 above the reactor vessel 26 and positioned to directthe formed atomized fog 46 from a top surface 58 of liquid 13 in thereactor vessel 26 to the fog outlet 19.

An additional feature that may be provided in certain circumstancesincludes a means for heating the fog 46, which has been found to reducethe size of the fog particles. Such a heating means may comprise, forexample, a coil 59 (FIG. 10) positioned along the exhaust path.

It will be understood by one of skill in the art that many variations onthe embodiment discussed above may be contemplated. For example, theexhaust system may include a diverter element 60 as illustrated in FIG.9.

In addition, various alternate means may be employed to support theultrasonic heads 43, as shown in the flotation elements of FIGS.11A-11C, wherein a foam floater 61 (FIG. 11A), a sealed air cavity 62(FIG. 11B), or a floater ring 63 (FIG. 11C) may be used to support thetray 26 and the heads 43.

Further, the reactor tray 26 may include a plurality of reactor vessels26,26′26″ positioned adjacent each other, the top edge 41 of a firstreactor vessel 26 above the top edge 41′ of a second reactor vessel 26′,and so on. In this embodiment the liquid transferring means is adaptedto transfer liquid 13 into the first reactor vessel 26, therebypermitting a cascade of liquid from the first reactor vessel 26 into thesecond reactor vessel 26′ and thence into the third reactor vessel 26″during operation.

The shape of the device as illustrated herein is not intended to belimiting. For example, in an alternate embodiment 10′ shown in FIG. 12,the tank 11′ may have a chimney 21′ at the front of the tank, with aliquid inlet 60 toward the rear of the tank 11′.

Another important feature of the present invention includes the liquidcomposition used for sanitizing spaces, and a method of making thiscomposition. The invention is not intended to be limited, however, tothe precise composition and proportion of ingredients in the liquid.

In a preferred embodiment, the composition is made as follows: 40gallons of clean, carbon-filtered water is added to a clean plastic orstainless steel vessel, and a mixer is turned on. 1 pound of sodiummetasilicate pentahydrate is mixed into the water slowly, and mixingcontinues for 5 min. With the mixer still running, a clean plastic pailis used to remove 1 gal of mixed solution for use in a pre-blendingstep. 70 ml of SE25 (Wacker Chemie AG, Munich, Germany), asilicone-based antifoaming agent, is added to the pail, and mixed usinga clean plastic rod until the solution is blended thoroughly. At thispoint the solution will appear to be a cloudy micro-emulsion. 60 ml ofK-2 surfactant (Lonza Chemical Corporation, Switzerland), used as amolecular coupler, is mixed slowly into the micro-emulsion untilthoroughly blended.

With the mixer running, the pre-blend is added back into the firstvessel at a rate of 180 ml per min while the mixer is running, and themixer continues to run after the pre-blend has been added. Into a clean1000-ml beaker containing 700 ml distilled water, 2 oz ofPalaklor-1103041 (Pylam Products Company, Inc., Tempe, Ariz.) is added.This substance comprises a dye base for its ultraviolet reflectivetraits and can be used as tracer. The Palaklor is not necessary for thesanitizing aspect of the inventive composition, and can therefore beomitted if a tracer is not desired in the mixture. The mixture is shakenfor 1 min, and is then added to the first vessel with continued mixing.

Water is added to the first vessel to bring the volume up to 55 gal, andmixing continues for 15 min. When blending is complete, the mixturestands for 1 h prior to packaging. For use, the mixture is diluted 1:1with water.

To the mixture may be added sanitizing, disinfectant, and/orinsecticidal elements such as, but not intended to be limited to,di-N-alkyl(C₈₋₁₀)—N,N-dimethylammonium chloride,N-alkyl(C₁₀₋₁₂)dimethylammonium chloride, tetrasodium ethylenediaminetetraacetate, sodium ethanol, 2-propanol, pyrethrum,octylphenoxypolyethoxyethanol (a nonionic surfactant), quaternaryammonia, formaldehyde, and peroxide.

In the foregoing description, certain terms have been used for brevity,clarity, and understanding, but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, because suchwords are used for description purposes herein and are intended to bebroadly construed. Moreover, the embodiments of the apparatus andcomposition illustrated and described herein are by way of example, andthe scope of the invention is not limited to the exact details ofconstruction, constituents, and proportion.

1. A device for sanitizing a space comprising: a tank having an interiorspace for holding an aqueous sanitizing liquid; a reactor vesselsupported within the tank interior space and above a bottom of the tank;an ultrasonic head comprising an ultrasonically vibratable disc forgenerating ultrasonic energy, the ultrasonic head positionable withinand beneath a top edge of the reactor vessel; means for transferringliquid from the tank interior space to the reactor vessel to a level forsubstantially submerging the ultrasonic head; means for vibrating thedisc to form an atomized fog of particles from the aqueous sanitizingliquid; and means for exhausting the formed atomized fog from thereactor vessel to a space exterior of the tank.
 2. The space-sanitizingdevice recited in claim 1, wherein an area of the reactor vessel topsurface is substantially larger than an area of a top of the tank. 3.The space-sanitizing device recited in claim 1, wherein the tank has aliquid line aperture adjacent a top of the tank and a liquid outletadjacent the tank bottom.
 4. The space-sanitizing device recited inclaim 3, wherein the transferring means comprises a liquid line in fluidcommunication with the liquid outlet at an inlet end and with thereactor vessel at an outlet end, the liquid line passing through theliquid line aperture between the inlet end and the outlet end.
 5. Thespace-sanitizing device recited in claim 4, wherein the transferringmeans further comprises a pump in the liquid line operable to moveliquid through the liquid line from the tank interior space beneath thereactor vessel to an interior space of the reactor vessel.
 6. Thespace-sanitizing device recited in claim 5, wherein the liquid linecomprises a substantially clear material, a portion of the liquid lineexterior of the tank thereby serving as an indicator of a liquid levelwithin the tank interior space when the pump is not operating.
 7. Thespace-sanitizing device recited in claim 1, further comprising a levelsensor positioned within the reactor vessel at a height for sensing asubmersion of the ultrasonic head, the level sensor in signalcommunication with means for disabling the vibrating means if theultrasonic head is not submerged.
 8. The space-sanitizing device recitedin claim 1, wherein the tank comprises a material adapted to maintain astatic charge.
 9. The space-sanitizing device recited in claim 8,wherein the tank comprises a high-density polyethylene material.
 10. Thespace-sanitizing device recited in claim 1, wherein the tank furthercomprises a fog outlet positioned adjacent a top of the tank extendingfrom the tank interior space to the tank exterior space, and wherein theexhausting means comprises a chimney having a bore therethrough, thebore having a first end in fluid communication with the fog outlet and asecond, generally upwardly directed end open to the tank exterior space.11. The space-sanitizing device recited in claim 10, wherein the fogoutlet is positioned on a vertical wall of the tank, and wherein thechimney bore has an elbow therein between the first and the second end.12. The space-sanitizing device recited in claim 1, wherein theexhausting means comprises a fan positioned within the tank interiorspace above the reactor vessel and positioned to direct the formedatomized fog from a top surface of liquid in the reactor vessel to a fogoutlet positioned adjacent a top of the tank extending from the tankinterior space to the tank exterior space.
 13. The space-sanitizingdevice recited in claim 1, wherein the top edge of the reactor vesselhas a plurality of notches therealong for permitting liquid to passtherethrough but for substantially blocking foam from passingtherethrough.
 14. The space-sanitizing device recited in claim 1,wherein the reactor vessel has a drain hole extending from an interiorspace of the reactor vessel through to the tank interior space, thedrain hole positioned adjacent a bottom of the reactor vessel interiorspace.
 15. The space-sanitizing device recited in claim 1, wherein thereactor vessel comprises a substantially hollow lower section having aplurality of support legs extending from a bottom thereof and an uppersection comprising a bottom and an enclosing wall extending upwardlyfrom the upper section bottom adapted to contain liquid, the lower andthe upper sections affixable together with the upper section atop thelower section and positionable within the tank interior space with thesupport legs contacting a bottom surface of the tank interior space. 16.The space-sanitizing device recited in claim 1, wherein the ultrasonichead comprises a plurality of ultrasonic heads, each comprising aplurality of vibratable disks affixed to a top surface of the respectiveultrasonic head.
 17. The space-sanitizing device recited in claim 16,wherein each vibratable disk comprises a substantially toroidal O-ringseat, a Viton O-ring seated on the O-ring seat, a ceramic diskpositioned atop the O-ring, and a substantially toroidal retaining ringpositioned in circumferentially retaining relation atop the ceramicdisk.
 18. The space-sanitizing device recited in claim 1, wherein thereactor vessel comprises a flotation element adapted to permit thereactor vessel to float upon a liquid surface within the tank interiorspace.
 19. The space-sanitizing device recited in claim 1, wherein thereactor vessel comprises a plurality of reactor vessels positionedadjacent each other, the top edge of a first reactor vessel above thetop edge of a second reactor vessel, and wherein the liquid transferringmeans is adapted to transfer liquid into the first reactor vessel,thereby permitting a cascade of liquid from the first reactor vesselinto the second reactor vessel during operation.
 20. Thespace-sanitizing device recited in claim 1, further comprising means forheating the formed atomized fog for reducing a size of the fogparticles.
 21. A method for sanitizing a space comprising the steps of:placing an aqueous sanitizing liquid into an interior space of a tank;transferring liquid from the tank interior space to a reactor vesselsupported within the tank interior space and above a bottom of the tank;vibrating an ultrasonically vibratable disc of an ultrasonic head togenerate ultrasonic energy, the ultrasonic head positioned within andbeneath a top edge of a reactor vessel and submerged with thetransferred liquid to form an atomized fog of particles from the aqueoussanitizing liquid; and exhausting the formed atomized fog from thereactor vessel to a space exterior of the tank.
 22. The space-sanitizingmethod recited in claim 21, wherein the transferring step comprisespumping the sanitizing liquid through a liquid line in fluidcommunication with a liquid outlet in the tank at an inlet end and withthe reactor vessel at an outlet end, the liquid line passing through aliquid line aperture adjacent a top of the tank between the inlet endand the outlet end.
 23. The space-sanitizing method recited in claim 22,wherein the liquid line comprises a substantially clear material, andfurther comprising the step of using a portion of the liquid lineexterior of the tank as an indicator of a liquid level within the tankinterior space when the pump is not operating.
 24. The space-sanitizingmethod recited in claim 21, further comprising the steps of monitoring asubmersion level of the ultrasonic head and, if the ultrasonic head isnot submerged, disabling the vibrating step.
 25. The space-sanitizingmethod recited in claim 21, wherein the tank further comprises a fogoutlet positioned adjacent a top of the tank extending from the tankinterior space to the tank exterior space, and wherein the exhaustingstep comprises exhausting fog through a chimney having a boretherethrough, the bore having a first end in fluid communication withthe fog outlet and a second, generally upwardly directed end open to thetank exterior space.
 26. The space-sanitizing method recited in claim21, wherein the top edge of the reactor vessel has a plurality ofnotches therealong for permitting liquid to pass therethrough but forsubstantially blocking foam from passing therethrough.
 27. Thespace-sanitizing method recited in claim 21, further comprising thestep, when a fog is not being formed, of permitting liquid in thereactor vessel to drain through a drain hole extending from an interiorspace of the reactor vessel through to the tank interior space, thedrain hole positioned adjacent a bottom of the reactor vessel.
 28. Thespace-sanitizing method recited in claim 21, further comprising the stepof heating the formed atomized fog for reducing a size of the fogparticles.
 29. A method for sanitizing a space comprising the steps of:placing an aqueous sanitizing liquid into an interior space of a tank,the aqueous sanitizing liquid comprising water, sodium metasilicatepentahydrate, a surfactant, and an antifoaming agent; transferringliquid from the tank interior space to a reactor vessel supported withinthe tank interior space and above a bottom of the tank; vibrating anultrasonically vibratable disc of an ultrasonic head to generateultrasonic energy, the ultrasonic head positioned within and beneath atop edge of a reactor vessel and submerged with the transferred liquidto form an atomized fog of particles from the aqueous sanitizing liquid;and exhausting the formed atomized fog from the reactor vessel to aspace exterior of the tank.
 30. The method recited in claim 29, furthercomprising the step, prior to the placing step, of making the aqueoussanitizing liquid, comprising the steps of: mixing sodium metasilicatepentahydrate into water to form a first solution; remove a small amountof the first solution; mixing an antifoaming agent into the removedsmall amount of first solution to form a second solution; adding asurfactant to the second solution; adding the second solution into theremaining first solution to form a third solution; and adding a secondantifoaming agent to the third solution.